Pruning Hydrangeas 101: Everything You Need to Know for Beautiful Blooms

As a gardening enthusiast, I know how important it is to maintain the health and beauty of the plants in my garden. And one of my favourite plants to care for is the hydrangea. But how do you prune hydrangeas without them drooping?

Hydrangeas produce beautiful, showy blooms that are sure to impress. However, to ensure that your hydrangeas continue to bloom year after year, it is crucial to know when and how to prune them. 

In this article, I’ll share everything you need to know about pruning hydrangeas.

Introduction to Pruning Hydrangeas

Pruning is the process of cutting back a plant to promote new growth and improve its overall health. And when it comes to hydrangeas, pruning plays a critical role in ensuring that the plant produces beautiful blooms year after year. 

Pruning hydrangeas can also help maintain the plant’s size and shape, which is particularly important if you are growing hydrangeas in a small space.

Why Pruning is Important for Hydrangeas

OK — so Madonna may “loathe” them, but most of the rest of us love those huge, bountiful blooms in rainbow colours that bring beauty and structural interest to our gardens. 

However, hydrangeas can grow huge. So, pruning hydrangeas is essential for several reasons: 

• Helps remove dead or diseased wood, which can prevent the spread of disease to other parts of the plant. 
• Helps improve air and sunlight circulation, which are both essential for the health of the plant. 
• Help promote new growth and encourage the plant to produce more blooms.

When to Prune Hydrangeas

The best time to prune hydrangeas depends on the variety of hydrangea. 

Old Wood Hydrangeas

Hydrangeas that bloom on old wood (last year’s growth), such as the bigleaf hydrangea (Hydrangea macrophylla) or oakleaf hydrangea (Hydrangea quercifolia), should be pruned immediately once they’ve finished blooming. 

This will give the plant enough time to produce new growth and set buds for next year’s blooms.

New Wood Hydrangeas

Hydrangeas that bloom on new wood (this year’s growth), such as the panicle hydrangea (Hydrangea paniculata) or smooth hydrangea (Hydrangea arborescens), can be pruned in late winter or early spring. 

You can prune these types of hydrangeas back hard, as they will produce new growth and blooms on the current season’s growth.

How to Prune Hydrangeas – A Step-by-Step Guide

Pruning hydrangeas may seem intimidating, but it’s actually relatively simple. 

Here’s a step-by-step guide:

1. Remove dead or diseased wood from the plant. This will help prevent disease and ensure the plant looks healthy.
2. Remove weak or crossing branches. These branches can rub against each other, causing damage to the plant and preventing proper air circulation.
3. For bigleaf and oakleaf hydrangeas, remove about one-third of the oldest stems at ground level. This will encourage the plant to produce new growth and set buds for next year’s blooms.
4. For panicle and smooth hydrangeas, prune the plant back to about 12 inches from the ground. This will encourage the plant to produce new growth and blooms on the current season’s growth.
5. Remove dead flower heads to improve the plant’s appearance and promote new growth.

Do’s and Don’ts of Pruning Hydrangeas

When pruning hydrangeas, there are a few do’s and don’ts to keep in mind.

DO: 

• Prune at the right time of year for your specific hydrangea type 
• Use sharp, clean pruning shears to prevent damage to the plant 
• Cut back to a healthy bud or branch to promote new growth
• Remove any dead or diseased wood to prevent the spread of disease
• Remove any weak or crossing branches to improve air circulation

DON’T: 

• Prune too late in the season, as this can remove next year’s buds  
• Use dull or dirty pruning shears, as this can damage the plant 
• Prune too much, as this can stunt the plant’s growth and reduce blooming

What affects the colour of a hydrangea bloom?

You could be mistaken in thinking that the colour of your hydrangea bloom relies on the specific variety of the plant. But you might be surprised to discover that that’s not the case. 

The colour of a hydrangea is affected by the pH level of the soil it grows in. 

Yes, you read that correctly. 

Acidic soil (pH lower than 6.0) produces blue or lavender-blue hydrangea blooms, while alkaline soil, with a pH above 7.0, promotes pinks. 

Some gardeners have reported success in turning their hydrangeas blue by applying coffee grounds to the soil, as they make the soil more acidic. 

Additionally, some bigleaf hydrangeas can change flower colours from pink to blue, or vice versa, based on the availability of aluminium ions in the soil. 

Every day’s a school day! 

Tools Needed for Pruning Hydrangeas

To prune hydrangeas, you will need a few essential tools. These include:

• Sharp pruning shears or loppers
• Gardening gloves
• Safety glasses
• Disinfectant spray or rubbing alcohol (to clean pruning shears)

Tips for Maintaining Healthy and Beautiful Hydrangeas

Pruning is just one aspect of hydrangea care. 

Here are some extra tips to help you maintain healthy and beautiful hydrangeas:

• Water regularly, especially during hot and dry weather
• Fertilize in the spring with a balanced feed
• Mulch around the plant’s base to help retain moisture and suppress weeds
• Provide partial shade during the hottest part of the day
• Monitor for pests and diseases and take action as needed

FAQs

Ready to prune hydrangeas?

Pruning hydrangeas is a crucial aspect of plant care that can help promote new growth, improve air circulation and sunlight exposure, and encourage the plant to produce more blooms. 

By following the tips and techniques outlined in this article, you can ensure that your hydrangeas remain healthy and beautiful year after year. Remember to prune at the right time of year, use sharp and clean pruning shears, and avoid common pruning mistakes. 

With a little care and attention, your hydrangeas will continue to impress for years to come.

Happy pruning!